In the 19th century, the first set of studies around certain "rhythms" or "life cycles" started and were successfully called Biorhythms. The word Biorhythm is composed of two Greek terms - "bios" and "rhythmos" which mean "life" and a constant or periodical "rhythm". The theory of Biorhythms defines and measures 3 fundamental cycles of humankind - physical, emotional and intellectual.

Wilhelm Fliess, a respectable and well-known doctor in Berlin, started a pioneering study on biorhythms in 1890. Fliess, who had observed 23 and 28 day cycles in his own patients, started collecting statistics on periodical occurrences of fevers, child illnesses and

predisposition to illness and death. With these statistics, Fliess believed to have studied fundamental "periods" in human life.
Following this, Dr. Fliess developed two of the major theories of biorhythms. The first sustains that Nature gave man a "body clock" which measures the time from when he is born and continues throughout his life. The 2nd affirms that one of these body clocks set for 23 day cycles influences the physical cycle and the other, regulated for 28 days, influences the emotive part of the individual and his level of sensitivity.

Dr. Sigmund Freud

One of Fleiss' contemporaries was important in accepting these ideas. He was Sigmund Freud, a man of
extremely revolutionary ideas for his time. At the start of his career, Freud showed great interest and admiration for Fliess' theories and soon they became close friends.

Important ideas tend to spread quickly in the scientific community. Dr. Hermann Swoboda, a Professor of Psychology at Vienna University, read about Fleiss' work when he himself was young. At the turn of the century, he researched, studied and wrote on the subject of Biorhythms.

At the turn of the century, he researched, studied and wrote on the subject of Biorhythms. Swoboda, who singled out periodicity
in dreams and particular thought processes, in fevers, asthma, heart attacks and illnesses, was convinced of the validity of Fleiss' observations in cycles of 23 and 28 days.